<h2>Comments</h2>
<pre><code>-- Single line comment
/* Multi-line
comment */</code></pre>

<h2>Operators</h2>
<pre><code>l_message  := 'Hello ' || place_in;</code></pre>

<h2>Keywords</h2>
<pre><code>CREATE OR REPLACE PROCEDURE
hello_place (place_in IN VARCHAR2)
IS
  l_message  VARCHAR2 (100);
BEGIN
  l_message  := 'Hello ' || place_in;
  DBMS_OUTPUT.put_line (l_message);
END hello_place;

DECLARE
  l_dept_id
  employees.department_id%TYPE := 10;
BEGIN
  DELETE FROM employees
       WHERE department_id = l_dept_id;

  DBMS_OUTPUT.put_line (SQL%ROWCOUNT);
END;

DECLARE
  l_message   VARCHAR2 (100) := 'Hello';
  l_message2  VARCHAR2 (100) := ' World!';
BEGIN
  IF SYSDATE >= TO_DATE ('01-JAN-2011')
  THEN
    l_message2 := l_message || l_message2;
    DBMS_OUTPUT.put_line (l_message2);
  ELSE
    DBMS_OUTPUT.put_line (l_message);
  END IF;
END;</code></pre>